Book Image

PHP 7 Programming Cookbook

By : Doug Bierer
Book Image

PHP 7 Programming Cookbook

By: Doug Bierer

Overview of this book

PHP 7 comes with a myriad of new features and great tools to optimize your code and make your code perform faster than in previous versions. Most importantly, it allows you to maintain high traffic on your websites with low-cost hardware and servers through a multithreading web server. This book demonstrates intermediate to advanced PHP techniques with a focus on PHP 7. Each recipe is designed to solve practical, real-world problems faced by PHP developers like yourself every day. We also cover new ways of writing PHP code made possible only in version 7. In addition, we discuss backward-compatibility breaks and give you plenty of guidance on when and where PHP 5 code needs to be changed to produce the correct results when running under PHP 7. This book also incorporates the latest PHP 7.x features. By the end of the book, you will be equipped with the tools and skills required to deliver efficient applications for your websites and enterprises.
Table of Contents (22 chapters)
PHP 7 Programming Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Writing your own iterator using generators


In the preceding set of recipes we demonstrated the use of iterators provided in the PHP 7 SPL. But what if this set doesn't provide you with what is needed for a given project? One solution would be to develop a function that, instead of building an array that is then returned, uses the yield keyword to return values progressively by way of iteration. Such a function is referred to as a generator. In fact, in the background, the PHP engine will automatically convert your function into a special built-in class called Generator.

There are several advantages to this approach. The main benefit is seen when you have a large container to traverse (that is, parsing a massive file). The traditional approach has been to build up an array, and then return that array. The problem with this is that you are effectively doubling the amount of memory required! Also, performance is affected in that results are only achieved once the final array has been returned...